Generic spider

use case - generic spider has useful methods for common crawling actions such as following all links on a site based on certain rules, crawling from Sitemaps, or parsing an XML/CSV feed

CrawlSipder

rules - objects that define crawling behavior
parse_start_url - a method that can be overriden to parse the initial responses and must return

• either an Item
  object

• a Request
  object

• or an iterable containing any of them

Rules

scrapy.spiders.Rule
can declare multiple rules for followed links, always add a , at the end

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• link_extractor defines how links will be extracted from each crawled page
• allow/deny - only allow or ignore domains
• callback - calling methods to perform crawling on the response; if no callback is specified, follow is default to True

avoid calling parse since this is reserved for CrawlSpider to use it to set up the rules

• follow - a boolean if set to true extract all links on the page

Scrapy filter out duplicate link by default
beware that start_urls should not contain trailling slash
works

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does not work

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• process_links - filter purpose